Abstract: This thesis took apart the unordered label tree matching into tree structure matching and tree label semantic matching. By combined with the tree structure matching and semantic matching, the thesis changed the traditional tree matching algorithms into approximately matching, and a metadata retrieval method based on three-level tree approximately matching model was put forward. According to this new retrieval method, the accuracy and recall rates would be adjusted by different requirement of users. In the end, this thesis brought forward the retrieval process of XML-oriented metadata, and gave out the applied design of metadata approximately match. The results of experiments prove that the approximately matching model is feasible and efficient in the application of retrieval XML metadata.

Key words: XML, metadata retrieval, approximately matching, retrieval recall rate, retrieval accuracy rate

摘要： 将无序标签树匹配分解为树结构匹配和标签语义匹配,采用树结构匹配和语义匹配相结 合的方法,对传统树匹配算法进行了改进,提出了近似匹配概念,并针对元数据XML描述的结构化特 征,设计了一种基于三层近似匹配模型的元数据检索方法。这种检索方法可根据用户的不同需求有 效地调节元数据的查准率和查全率。最后构造了基于近似匹配模型的元数据查询系统原型,实验证 明近似匹配模型在元数据检索应用中具有可行性和高效性。

关键词: 可扩展标记语言, 元数据检索, 近似匹配, 查全率, 查准率